Narrow Spectrum Solid State Lighting Device for High S/P Ratio
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Solution Overview
Problem
Conventional solid state lighting devices face challenges in achieving high efficacy, good color reproduction, and color stability, particularly in maintaining elevated Scotopic/Photopic (S/P) ratios and gamut area index values within desirable Correlated Color Temperature (CCT) ranges, such as 2700K to 5000K.
Innovation Solution
The use of multiple electrically activated solid state light emitters with narrow spectral outputs, specifically including emitters with dominant wavelengths in the ranges of 485-505 nm, 526-545 nm, and 615-625 nm, to achieve high gamut area index values and elevated S/P ratios, with aggregate emissions optimized for specific CCT ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional solid state lighting devices use broad spectrum emitters, then they achieve high luminous efficacy, but they fail to provide good color reproduction and elevated S/P ratios
Solution Approach 1:
The patent segments the broad spectrum emission into multiple narrow spectral output emitters with specific dominant wavelengths (e.g., 480-500nm blue, 530-550nm green, 600-650nm red). Each emitter targets a specific wavelength range to collectively cover the visible spectrum while maintaining narrow bandwidths, thereby achieving both high efficacy and superior color reproduction including elevated S/P ratios
Solution Approach 2:
The patent employs a composite emitter architecture combining multiple solid state light emitters with narrow spectral outputs. This composite structure integrates emitters with different dominant wavelengths to create a unified lighting system that delivers broad spectral coverage through coordinated narrowband emissions, resolving the contradiction between efficacy and color quality
2Use of energy by moving object
If conventional solid state lighting devices use phosphor-converted LEDs, then they achieve high luminous efficacy, but they fail to maintain color stability and elevated S/P ratios across operating conditions
Solution Approach 1:
The patent extracts the phosphor conversion layer from the traditional LED structure and replaces it with direct narrow spectral output emitters. This removal of the phosphor conversion step eliminates the wavelength shifts and color instabilities inherent in phosphor-based systems, while maintaining high efficacy through direct emission from multiple targeted wavelength sources
Solution Approach 2:
The patent changes the emission parameter from broad spectrum (phosphor-converted) to narrow spectral output with specific dominant wavelengths. By controlling the spectral parameters of individual emitters and their relative intensities, the system achieves stable color reproduction and elevated S/P ratios across varying operating conditions
3Reliability
If solid state lighting devices use multiple emitters with different dominant wavelengths, then they improve color rendering, but they increase device complexity
Solution Approach 1:
The patent designs each narrow spectral output emitter to serve multiple functions: providing luminous efficacy, contributing to color rendering, and influencing S/P ratio. This multi-functionality reduces the need for additional specialized components, as each emitter simultaneously addresses multiple performance requirements, thereby managing device complexity while improving color rendering
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the S/P ratio and gamut area index values, providing improved color rendering and energy efficiency, suitable for various lighting applications including outdoor and automotive lighting.
Implementation Method 1
A solid state lighting device may include, for example, at least one organic or inorganic light emitting diode ('LED') or a laser
Implementation Method 2
at least one solid state light emitter including a narrow spectral output with a full width-half maximum emission value of no greater than 30 nm
Data Source
AI summary
A multi-emitter solid state lighting device includes at least one narrow spectral output solid state light emitter, such as may be in the green range, having a full width-half maximum emission value of no greater than 30 nm. First, second, and third electrically solid state emitters may include dominant wavelengths in the ranges of 485-505 nm (or 491-505 nm), 526-545 nm, and 615-625 nm. Aggregate emissions of a solid state lighting device may comprise a scotopic/photopic (S/P) ratio value that exceeds threshold values for conventional white light-emitting devices including at least one phosphor-converted LED by at least 10%, 20%, 30%, or 40%, in combination with reasonably high gamut and brightness, over a range of desired CCT values.